2015 Giant Defy Endurance Bike

The top-of-the-line Defy Advanced SL 0 comes stock with Shimano Dura-Ace Di2 and Zipp 202 Disc carbon clinchers.

Giant has made a giant-sized statement. Last week at a press event in Scotland, the world's largest bike maker rolled out a fully revamped version of its Defy endurance road bike, claiming it's both the lightest road frame it's ever produced (890 grams for size medium Advanced SL), and that it smoked comparable competition when lab tested for weight, stiffness and compliance (more details below).

Perhaps more significant is that Giant is going all in with disc brakes, outfitting all eight carbon fiber 2015 Defy models with the burgeoning road braking standard. Top of that line is the wallet-busting Defy Advanced SL 0, which comes stock with Shimano Dura-Ace Di2 shifting, Zipp 202 Disc carbon clinchers, and a $10,300 price tag. If you want traditional rim brakes (and/or to spend a whole lot less money) you'll need to choose from one of five lower-tier alloy models.

The development project started with a basic goal: make a Defy with disc brakes, but add no weight and strike the coveted balance between stiffness and compliance. "This was a purely engineering driven project," said Jon Swanson, Giant's global road category manager. "There are no gimmicks and no fluff. The only thing that did not change between the new Defy and its predecessor was the geometry."

2015 Giant Defy Endurance Bike

An overlay of the old under the new Defy shows that geometry indeed remains all but unchanged.

Swanson's knock on "gimmicks" was clearly aimed at the competition, many of which use various add-in bump-absorbing technologies in their endurance road frames; see Zertz (Specialized Roubaix) and IsoSpeed Decoupler (Trek Domane) for examples. "It's not easy to make a frame without stuff in it," added Swanson. "I had to fight to not just add something in so we can show a picture in a magazine."

Instead, Swanson and his team claim to have increased compliance primarily through the use of the D-Fuse integrated seatpost in the two Advanced SL models, a design originally used in Giant's top end TCX cyclocross bikes. The thin D-shaped post is claimed to add 12mm of ride-smoothing flex, but have no effect on power transfer. Once cut, there is 25mm of adjustment, which Giant feels is adequate to alleviate concerns about resale, a common complaint leveled at integrated post designs. However, that doesn't solve potential problems of travel or test rides.

2015 Giant Defy Endurance Bike 2015 Giant Defy Endurance Bike

The new Defy uses two forms of its ride smoothing D-Fuse seatpost. Top end SL models utilize an integrated set-up, while mid-tier bikes have an integrated seat clamp.

The rest of the composite frame models use a more traditional seatpost binder that has an expander bolt easily be accessed at the top tube. Swanson says the ride characteristic of the two systems will vary some, and the non-integrated posts are less stiff and a little heavier.

All the new frames also utilize dramatically thinned compliance-enhancing seat stays, which attach lower on the seat tube. Ride feel is further enhanced by the stock 25c tires, and Swanson says 28s are no problem.

"The stays are basically as thin as we can possibly make them while keeping them hollow," explained Swanson of the leaf spring design. "By keeping the stays hollow and eliminating the need for a brake bridge, we get vertical compliance without sacrificing stiffness. Lowering the junction point gives the frame balance. The upper half of the bike is compliant, the lower half maintains stiffness."

Check out the video below to see the integrated seatpost in action.

httpv://www.youtube.com/watch?v=qylOHWklGX8

Weight was also a huge design driver. Swanson says the top end frame is the lightest road frame Giant has ever produced. "The perception is that with road disc you have to pay a weight penalty," said Swanson. "We approached it as how do we offset that weight. And we actually dropped 50 grams on our top end frames, which is pretty significant when you see our competition having to add 40-50 grams to get disc tabs on."

That weight was shed in part by using hollowed carbon dropouts, eliminating the brake bridge, and generally minimizing the need for reinforcement frame material by reducing the number of holes in the carbon frame. The front brake hose is routed externally; all other cables/hoses go into one side of the frame because when you punch a hole in frame you have to add weight with reinforcing material. Instead Giant made a single slightly larger hole on the non-driveside.

"That's where having our own factory is huge," said Swanson. "From conception to in-house engineering to design to development to prototyping, all the way through manufacturing, it's all completely in house and completely controlled by Giant. The only thing we get from the outside is raw carbon fiber. We sit in offices above factory floor and if there is a problem or question, we can simply walk down a flight of stairs and are right in front of it. That level of control is huge and we feel it's a massive advantage over everyone else. Nobody else has that level of control."

Giant also opted for traditional quick releases rather than thru-axles. Swanson said this was both a weight saving measure, and a nod to the wait-and-see approach the company is taking toward the increasing use of disc brakes on road bikes, but the lack of an established standard when it comes to axles.

"People will say that once in a while you can get your rim brakes to hit your wheel so wont the same thing happen with rotors," explained Swanson. "But that's a wheel issue, not the core axle assembly. When there is an industry standard that goes beyond a couple third party players, and there are the same tolerances with the same designs, then we'll go with that. But at this point I was not comfortable building a product that would lock someone in to a limited number of wheels."

2015 Giant Defy Endurance Bike 2015 Giant Defy Endurance Bike

Bikes come stock with 25c tires (pictured) and are rated for 28c max. But you might be able to sneak a 30 in there. The headtube and fork integrate nicely.

Swanson did admit that moving to a thru-axle would have allowed for less material in the fork, and speculated that eventually 12mm will become the industry standard.

"Right now there are multiple conversations happening between a few of the big brands and everyone is talking the same talk," he said. "If it was up to me it would be done by now. But we still need the collaboration of the big brands to come together. I think 12mm is a good number. It's a number that gives enough stiffness that you can remove material from the fork leg, and I think 12mm thru-axles can be made light and still be stiff. But no matter where we end up, it also needs to have true quick release functionality so you can get wheels on and off quickly."

In an attempt to validate all the highlights of the new Defy, Giant says it conducted a series of comparative tests, focusing on weight, stiffness and compliance. The test field included the new Defy Advanced SL frame, along with Cannondale's Synapse Hi-MOD Disc, the Specialized S-Works Roubaix SL4 Disc, and Trek's Domane 6 Disc. Not surprisingly, the information shared painted Giant in glowing light.

Weight comparison was based on size medium/56cm production frames with fork, headset, derailleur hangers and seatpost/ISP. Stiffness was tested by fixing the rear drop-out, then measuring how much force it took to move the frame. Pedaling stiffness looked at force put into the bottom bracket with front end fixed and the rear end placed in a dummy hub. Bikes were then leaned at an angle representative of sprinting to measure how much force it took to deflect the bottom bracket side to side.

Finally, Giant looked at compliance, using methods created by a third-party auto/motorcycle tester. This pair of tests measured the amount and effect of vibration transmitted to a rider's hands, and the force coming through the saddle. Giant, as illustrated in these four screenshots displayed during the press launch, claims it topped the weight and stiffness comparisons, and was the second most compliant behind Cannondale's Synapse Hi-MOD Disc.

2015 Giant Defy Endurance BikeWeight comparisons used size medium, painted and decaled production frames.

2015 Giant Defy Endurance BikeIn the compliance test, framesets were locked at the fork dropouts, held loosely at the rear dropouts, and then force was applied to a dummy crank. The mower the number, the more compliant, says Giant.

2015 Giant Defy Endurance BikeTest results were based on scenario where framesets were locked at the rear dropouts and side force was applied to the fork dropouts, simulating cornering and sprinting. The higher the number, the stiffer the bike claims Giant.

So who is this bike for? Swanson believes most people should be riding bikes like the new Defy. And generally speaking, we agree. Unless you're Captain Criterium Racer, endurance road bikes simply make more sense. "It's great for Giant to sell lots of Propel (aero road bikes) and TCR (race bikes)," added Swanson. "But if you look at people's position on those bike, you end up seeing a lot of spacers and flipped stems being used. With the Defy, people can really benefit from the geometry, and that's even more true now that you get the performance without compromising stiffness."

Head to page 2 to find read our first ride impressions, and see page 3 for a full breakdown of the line along with pricing and an extended photo gallery.

Also check back later this week for details on the all new Liv Avail women's endurance road bike line, along with highlights of Giant's new disc wheels and apparel.




Two-Day Test Ride

Our time in Scotland (on Giant's dime) included two days of riding the Defy Advanced SL 0 in and around the town of Pitlochry in the Scottish Highlands. (No other bikes were tested.) Ride No. 1 was an ever-rolling 55-mile loop with about 3,500 feet of climbing. Road surface ranged from smooth to awful. Scenery was off-the-charts beautiful. Ride No 2 was about 70 miles with 3,700 feet of uphill pedaling. Again, roads were rolling with surface conditions running the gamut and scenery overwhelming.

The partial time on bad roads was by design. Giant wanted the gathered media to get a sense of how the bikes performed when things got choppy. This is, after all, a bike Swanson says will definitely be raced at Paris-Roubaix as soon as the UCI lifts its ban on disc brakes. All that said, it's hard to fully disseminate the relative merits of any bike after just two days, so take this all with the usual shake of salt.

Among the highlights was top-tier spec that included Shimano Dura-Ace Di2 electronic shifting drivetrain, Zipp 202 Disc carbon clincher wheels, Shimano R785 disc brakes, plus a host of Giant branded parts, including its oversized Giant Contact SLR stem.

2015 Giant Defy Endurance Bike 2015 Giant Defy Endurance Bike

Occasionally rough roads and tons of great Scottish scenery provided an ideal testing ground for the new Giant Defy Advanced SL 0.

Also impressive with the ease of seat height adjustment. Yes, you have to deal with cutting your frame (best left to the pros at you local bike shop). But after that, fine-tuning is achieved with shims provided with the bike. It's not much different than adding or taking away stem spacers, and with a claimed 25mm of adjustment, you should be able to loan the bike to friends of similar height - or sell it to them down the road.

Equally impressive was the bike's sprinting and climbing chops. The Defy felt every bit as stiff and efficient as any race rig I've been aboard lately. Hop out of the saddle and take a dig and away you go, no hesitation or flex whatsoever. The bike also tracked well in corners, its relatively long wheel base providing a stable and predictable ride.

All was not perfect, though. While the rear end (via the D-Fuse integrated seatpost) did a fine job soaking up road buzz, there were times when my hands felt pretty beat up, especially when rolling over rough pavement. I couldn't help but wonder if front and rear compliance was slightly out of balance. Perhaps this could be alleviated with a set of 28c tires, a change I'd make immediately if this bike was mine to keep.

2015 Giant Defy Endurance Bike

Yes, phone booths still exist.

Also, while our test rig was relatively quiet, we noticed intermittent rattling coming from some of our fellow tester's bikes. Causes ranged from an internal Di2 battery coming loose inside the seatpost, to internal cables/hose slapping around inside various tubes. These are issues that can usually be resolved with a little detective work, but I honestly wonder if bikes not designed to be fully aero really derive true benefit from internal cable routing. Is the aesthetic of visible cables really that bad?

Bottom line, after our very brief test session, we'd give the $10,300 Defy Advanced SL 0 a solid A-minus, with the hope of logging additional test time in order to provide more thorough analysis. In the meantime, click over to page 3 for breakdown of the line along with pricing and an extended photo gallery. Giant says the new Defy models should be hitting bike shop stores this fall.



2015 Giant Defy Endurance Bike

The Defy Advanced SL 1 comes with Giant's P-SLR0 Disc WheelSystem carbon clinchers.

Model Year 2015 Giant Defy Product Line

Defy Advanced SL: The flagship series of the new range. Frames weigh a claimed 890 grams (size medium) and feature Giant's top-tier Advanced SL-grade composite and the new D-Fuse integrated seatpost, which has 12mm of flex to better absorb road vibration. The D-Fuse design also reduces weight compared to traditional round seatposts. Fork has a slightly curved leg designed to improve compliance. All frames disc brake only.

Defy Advanced SL 0 ($10,300)
Frame:
Advanced SL-Grade Composite, Integrated Seatpost
Shifters: Shimano R785 disc
Drivetrain: Shimano Dura-Ace Di2
Wheels: Zipp 202 Disc carbon clinchers

Defy Advanced SL 1 ($4950)
Frame
: Advanced SL-Grade Composite, Integrated Seatpost
Shifters: Shimano RS685 disc
Drivetrain: Shimano Ultegra
Wheels: Giant P-SLR0 Disc WheelSystem carbon clinchers

2015 Giant Defy Endurance Bike

The Defy Advanced Pro line switches over to an integrated seat clamp, but maintains the full composite steerer tube.

Defy Advanced Pro and Advanced Series:
Features similar overall design and frame technologies as Advanced SL models, including disc brakes and non-integrated D-Fuse seatpost. Frame made from mid-tier Advanced-Grade composite material. Advanced Pro comes with a full composite fork and composite OverDrive 2 steerer tube. Advanced models have hybrid steerers.

Defy Advanced Pro 0 ($4900)
Frame
: Advanced-Grade Composite
Shifters: Shimano R785 disc
Drivetrain: Shimano Ultegra Di2
Wheels: Giant P-SL0 Disc WheelSystem alloy clinchers

Defy Advanced Pro 1 ($3500)
Frame
: Advanced-Grade Composite
Shifters: Shimano RS685 disc
Drivetrain: Shimano Ultegra
Wheels: Giant P-SL0 Disc WheelSystem alloy clinchers

Defy Advanced 1 ($2600)
Frame
: Advanced-Grade Composite
Shifters: Shimano Ultegra
Drivetrain: Shimano Ultegra
Wheels: Giant P-R2 Disc alloy clinchers

Defy Advanced 2 ($2075)
Frame
: Advanced-Grade Composite
Shifters: Shimano 105
Drivetrain: Shimano 105
Wheels: Giant P-R2 Disc alloy clinchers

Defy Advanced 3 ($1750)
Frame
: Advanced-Grade Composite
Shifters: Shimano Tiagra
Drivetrain: Shimano Tiagra
Wheels: Giant S-R2 Disc alloy clinchers

2015 Giant Defy Endurance Bike

The standard Defy models revert to traditional brakes on alloy frames.

Defy Series:
Aluminum bikes feature that same endurance geometry as the composite models. Top models in this series use Giant's ALUXX SL-grade aluminum and the D-Fuse non-integrated seatpost.

Defy 1 ($1375)
Frame
: ALUXX SL-Grade Aluminum
Shifters: Shimano 105
Drivetrain: Shimano 105
Wheels: Giant P-R2 alloy clinchers

Defy 2 ($1075)
Frame
: ALUXX SL-Grade Aluminum
Shifters: Shimano Tiagra
Drivetrain: Shimano Tiagra
Wheels: Giant S-R2 alloy clinchers

Defy 3 ($950)
Frame
: ALUXX-Grade Aluminum
Shifters: Shimano Sora
Drivetrain: Shimano Sora
Wheels: Giant S-R2 alloy clinchers

Defy 5 ($620)
Frame
: ALUXX-Grade Aluminum
Shifters: Shimano Claris
Drivetrain: Shimano Claris
Wheels: Giant S-R2 alloy clinchers